People who use catheters several times a day to empty their bladder are testing whether a daily antibiotic pill can cut their repeated urinary tract infections in half. Around one in five people who self-catheterise develop frequent, painful UTIs that require repeated antibiotic courses. Current guidelines offer no clear prevention strategy, leaving clinicians to guess between waiting for each infection or prescribing daily prophylaxis without solid trial evidence. This trial directly compares the two approaches in 372 adults across seven UK hubs, tracking infection rates, antibiotic resistance, quality of life, and cost to the NHS over 12 months. If the daily pill reduces infections by at least 20 per cent—from an average of three to 2.4 per year—the finding could change standard practice. Patients would gain fewer infections, fewer GP visits, and less disruption to daily life. The NHS would avoid the costs of treating preventable UTIs and hospitalisations. Crucially, the trial also monitors whether daily antibiotics breed resistant bacteria in urine and on the skin, addressing the central worry that prophylaxis might trade short-term relief for long-term treatment failure.
View original technical description
DESIGN: A pragmatic randomised, non-blinded, parallel group trial testing the experimental strategy of once-daily antibiotic prophylaxis against the control strategy of no prophylaxis over 12 months. Contingent valuation to estimate cost-benefits and a qualitative study to explore perception of benefit will be performed at the end of trial participation. Changes to bacterial ecology will be assessed by microbiological analysis of sequential urine specimens and perineal swabs. SETTING: We will establish seven trial hubs; Bristol, Cambridge, Southampton, Newcastle, Wakefield, Aberdeen, and Glasgow who will co-ordinate recruitment of participants from at least 40 secondary care sites and the four primary care research networks who have expressed an interest in the trial. TARGET POPULATION: Adult established users of CISC predicted to continue its use for at least 12 months who have suffered at least two episodes of CISC-related symptomatic UTI within the past 12 months. HEALTH TECHNOLOGIES BEING ASSESSED: Once-daily prophylactic antibiotic over 12 months using either nitrofurantoin 50 mg or trimethoprim 100 mg or cefalexin 250 mg as selected by clinician and participant. Tolerability will be assessed after four weeks and alternatives used as appropriate. The control is no prophylaxis with participants from both groups receiving usual care for symptomatic UTI. MEASUREMENT OF COSTS AND OUTCOMES: The primary outcome will be incidence of UTI defined as the combination of at least one symptom of UTI and the taking of a treatment antibiotic course for UTI recorded by participant log and validated by healthcare records. Cost-effectiveness will be assessed by the incremental cost per symptomatic UTI avoided using costs from NHS and other standard sources and measured from healthcare records, participant-completed health utilisation questionnaire, and time and travel questionnaire. Secondary outcomes include; incidence of microbiologically proven symptomatic UTI assessed by detection of at least 10,000 cfu/ml of no more than two bacterial isolates in a urine specimen; changes in quality of life over 12 months and during UTI episodes measured by the SF-36; rates of hospitalisation due to UTI from healthcare records; and changes to resistance patterns of bacterial isolates from sequential urine specimens and perineal skin swabs. Participant benefit will be further explored by treatment satisfaction questionnaire and qualitative analysis of interviews on exit. Adverse events will be recorded from participant log, questionnaire and healthcare records. Cost-utility using quality-adjusted life years derived from the SF-36 and cost-benefit using contingent valuation questionnaire on trial exit will be assessed. SAMPLE SIZE: We consider that a 20% reduction in UTI from an average of 3 to 2.4 episodes per year represents the minimum difference likely to change practice. Using the Poisson rate test, completion of the study by 158 participants in each arm, 316 in total, would give 90% power to detect this difference at the 5% level. A total of 372 would allow for a 15% attrition rate. We will approach approximately 750 eligible patients anticipating a 50% recruitment rate. For the qualitative component a purposive sample of up to 30 participants will be interviewed at 12 months and we aim to obtain contingent valuation from 200 participants.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know